Automatic needle threader for sewing machines



Oct. 23, 1956 s. SHAPIRO 2,757,671

AUTOMATIC NEEDLE THREADER FOR SEWING MACHINES Filed Dec. 15, 1954 asuds-sheet 1 A IN V EN TOR. SAMUEL SHAPIRo Oct. 23, 1956 s. SHAPIRO2,767,571

AUTOMATIC NEEDLE THREADER FOR swims MACHINES Filed Dec. 15. 1954 5Sheets-Sheet 2 fiAmuEL 5HAPIRO Oct. 23, 1956 s. SHAPIRO 2,

AUTOMATIC NEEDLE THREADER FOR SEWING MACHINES Filed Dec. 15, 1954 sSheets-Sheet a INVENTOR. SAMUE SHAPIRO United States Patent AUTOMATICNEEDLE THREADER FOR SEWING MACHINES Samuel Shapiro, Metuchen, N. 3.

Application December 15, 1954, Serial No. 475,467

6 Claims. (Cl. 112-225) This invention relates to a needle threadingattachment for a sewing machine, and more particularly, has reference toan improved attachment of the type stated, which is normally disposed inan out-of-the-way position in which it will not interfere with normalsewing operations, but which is readily shiftable longitudinally of theneedle into registration with the needle eye, to facilitate thethreading of the needle.

One important object of the present inevntion is to provide anattachment of the type referred to which will be a self-containedassembly adapted to telescopically receive the needle post, whereby saidassembly can be assembled with a minimum expense, and can be mountedupon the needle post with ease and with minimum interference to normalsewing operations.

Another object is to so design the device as to normally latch thethreading means in an elevated, out-of-the-way location, whilepermitting release of the latch by a remotely operated means.

Still another object is to improveupon the threading means that extendsthrough the eye of the needle, in such a way as to cause the thread tobe properly aligned with said threading means with maximum ease, and tocause,

further, the threading means itself to be properly aligned with the eyeof the needle, whereby to cause the thread to be extended through theeye merely by a single reciprocating movement of the threading means.

Still another object is to provide a needle threading attachment forsewing machines which can be manu-- factured at a relatively low cost,as an attachment for machines already in use.

Still another object is to provide a needle threadingattachment asstated which will be swift and sure in operation, rugged inconstruction, and compact in form.

, For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawings, and to the appended claims in which thevarious novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a front elevational view of a sewing machine equipped with athreading attachment formed in accordance with the present invention.

Fig. 2 is an enlarged front elevational view of the needle and of theattachment.

Fig. 3 is an elevational view of the needle and attachment as seen fromthe right of Fig. 2.

Fig. 4 is a view similar to Fig. 2 in which the threading attachment hasbeen lowered for threading of the needle.

Fig. 5 is a still further enlarged, fragmentary view partly in sideelevation and partly in longitudinal section of the needle and threadingattachment in the Fig. 4 position.

Fig. 6 is a bottom plan view of the plunger support block of theattachment, per se.

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Fig. 7 is an exploded perspective view of the removable, self-containedthreading assembly.

Fig. 8 is an exploded perspective view of the plunger per se.

Fig. 9 is a side elevational view of the needle post or assembly supportbar of the sewing machine, the threading attachment support tube beingtelescopically related thereto and being shown in longitudinal section.

Fig. 10 is a detail, enlarged section on line 1010 of Fig. 1 showing theremote control latch release means.

Fig. 11 is an enlarged, sectional view of the threading plunger andsupport block, with the plunger inserted through the eye of the needleduring an intermediate step of the threading operation.

Fig. 12 is a view similar to Fig. 11, still further enlarged, with theplunger retracted to pull the thread through the eye of the needle.

Fig. 13 is an enlarged, longitudinal sectional view on line 1313 of Fig.4. v

Fig. 14 is an enlarged, fragmentary perspective view of the needle perse.

Fig. 15 is a transverse sectional view on line 15-15 of Fig. 13.

Fig. 16 is an end elevational view of the sewing machine as seen fromthe left of Fig. l, with the end plate removed.

Fig. 17 is a similar view to Fig. 11 but showing a modified form of thisinvention.

The reference numeral 20 has been generally applied in the severalfigures of the drawing to a conventional sewing machine head. The needlethreading attachment constituting the present invention has beenillustrated in operative association to said head and to the needle, andincludes an elongated, open-ended, constant-diameter, threadingattachment support tube 22 having adjacent its lower end a threadedopening 24 in which is threadedly engaged a guide pin in the form of ascrew 26 extending through a smooth-walled opening formed in a U-shapedcollar 28 having at its lower end a hook-like guide 30 for the thread Tof the sewing machine.

An open-ended threader block support member 32 is formed (see Fig. 7)with a closed, longitudinal guide slot 34 intermediate its endsreceiving the reduced inner end of pin 26 (Fig. 15). The member 32 isthus held against rotation relative to the tube 22, but is shiftableupwardly and downwardly therein, with the extent of up-and-down movementbeing limited by the pin and slot means 26, 34.

Extending from end to end of the member 32 is a wide clearance slot 36,through which projects (Fig. 15) a needle lock screw 38, engaging thethickened head of a sewing machine needle 40 having a flat surface 42against which the screw 38 bears.

The needle has, at its lower end, the usual eye 44, through which thethread T is to be drawn when the needle is being threaded.

The threading attachment additionally includes a horizontally extending,generally rectangular plunger support block 46 having adjacent one end(Fig. 12) a vertical bore 48. A transverse notch 50, opening downwardlyupon the underside of the block, is in communication with the lower bore48, the notch opening upon a shallow, angular recess 52 formed in theunderside of the block.

Extending longitudinally and centrally of the block is a. plunger bore54, which, at that end of the block remote from the vertical bore 48,merges into a counterbore 56 which in turn merges into a threadedcounterbore 58 in which is threadedly engaged a screw 60. The screw 60is of the sleeve type, and provides a guide for a plunger 62 one end ofwhich projects outwardly from the block and has threaded thereon abutton 64. The plunger 62, within flat extension 68 proportioned toextend through the eye 44 as shown to particular advantage in Fig, ll.Guide pins 69 extend inwardly from the opposite sides of the block (Fig.6) and bear lightly against the opposite side surfaces of the, extension68, to properly center said extension Within the bore so thattheextension will pass through the eye 44 on every occasion. The pins 69can be threaded into the bore, so as to be adjustable transversely ofthe block for laterally shifting the blade-like extension within theplunger bore if necessary to properly align the extension with the eyeof the needle.

A spring 70 is circumposed about the plunge; within the counterbore 56,and is held under compression, one end ofthe spring bearing @ainst t ecollar 66 and the other end bearing against the inner end of thecounter.- bore 56., The spring 70, tending to expand, normally urges theplunger to the full line position of l3, but against, the restraint ofthe spring, one may press the plunger inwardly from the Fig. l or Fig.position to the Fig. 11 position, to extend the blade-like extension 63through the eye of the needle.

Formed on the free end of extension 68 is a hook 72, adapted to engagethe thread T when the thread is looped through the notch 59 in themanner shown in Fig. 13.

The block 46 is normally latched in an inoperative, upper position shownin Fig. 2, by means of a pivoted detent 74 having depending cars 76through which extends a pivot pin 73 carried by the block 46. A spring89 is interposed between the detent and the block, to normally urge thedetent to the position thereof shown in Fig. 2. The lower end of thetube 22 has a circumferential groove 82, the top edge of which may beslightly evcled in a commercial embodiment of the invention, and thedetent has a beveled inner end engageable in said groove when the blockis to be inoperatively disposed, thus to lock or latch the block in itsinopenative position.

To release the block, one need only press downwardly on the outer end ofthe detent. However, remote control means isdesirable for this purpose,since, in view of the smallness of the parts, it is not desirable thatone press directly upon the horizontally projecting block 46 and detentwith the finger, since this would tend to move the blockout of itsproper position over a period of time, causing the blade or extension 68to move out of alignment with the eye of the needle.

So as to prevent this, there is provided a dctent-engaging release pin88 formed upon one end of a tlexible cable housed in a cloth sheath r32.A bracket 84 is mounted upon the sewing machine head, and supports a pinhousin 86, from which the pin 83 projects.

At its other end, the cable, 90 is provided with a push button 94projecting laterally from a cable support bracket 96 of Z shape mountedupon the head 25!.

By pressing upon the button 94, one extends the pin 38, thus pressingdownwardly upon the detent 74 to disengage the detent from the groove82.

It will be seen that the tube 22, collar 28,, member 32, block 46,plunger, and detent provide a self-contained assembly, the parts ofwhich can be assembled separately and thenslipped telescopically onto aneedle post 6 of the sewing machine (Figs. 9 and 16). The needle post 96has, at its upper end, a head 98 increased slightly in diameter relativeto the main diameter of the. needle post, the head 98 being engageablein a holder 100 of the sewing machine. At its, lower end, the needlepost is formed with a tube support portion 106 of reduced thickness,having a cross-sectional shape such thatthe member 32 can slipthereover. in other words, the portion 106 is of a cross-sectional arealess than the inner diameter or cross-sectional area of, the tube 22 andthis defines, as shown in Fig. 9, a space between portion 106 and tube22, intowhich space the member 32.is snugly but s'lidably fittedwhen thetube 22 is placed over the needle post. The member 32 has opposed, flatinner surfaces and the portion 1060f the needletpost also has opposed,fiat surfacesengageable against the flatsurfaces of the member' 32. Themember 32 as previously noted herein is of partly cylindrical exteriorcross section, and this is true also of the portion lltl. All this isshown to particular advantage in Fig. 15.

Formed in the lower end of the portion 106 is an axial, downwardlyopening socket 16 8 for the needle 40, and communicating with the socketM53 is a threaded opening in which the screw 38 is threadedly engaged.Thus, the needle is locked in the socket llld, and can be readilyremoved without removal of the threading attachment, since the needieand the post constitute a unitary assembly separate from and distinctfrom the unitary assembly shown in Fig. 7.

In use, the threading assembly is slipped onto the needle post in themanner previously described. At its upper end, the tube 22 has a bayonetslot 104, and the needle post 96 has a laterally projecting pin 102engageable in the bayonet slot. Thus, the tube 22 is shifted upwardlyupon the post Q6, to cause the pin 102 to extend into the slot 104,after which the tube 22 is partially rotated to lock the pin in theinner end of the slot.

During normal use of the sewing machine, the member 32 and block 46 arein their upper, inoperative position shown in Fig. 2. If, however, it isdesired to thread the needle, one need only release the detent 74- inthe manner previously described, after which the block 46 is manuallyshifted downwardly to its Fig. 4 position. The member 32 is soldered orotherwise fixedly secured at its lower end to the block 46,. and thusmoves downwardly therewith, sliding in the space between the portion 106of the needle post and tube 22.

The downward movement of the block and the member 32 is limited by thelength of the slot 34, and at the lower limit of the travel of the blockand block support member, the blade 68 will be aligned with the eye 44as shown in Fig. 12.

One need only, at this time, pull the thread through the notch 50, afterfirst depressing the plunger to shift the same to its Fig. ll position.in other words, with the block 46 lowered, the plunger will initially bein the Fig. 5 position. The plunger is pressed inwardly through the eyeof the needle, after which the thread T is pulled upwardly within thenotch 50, to bear tightly against the bottom edge of the blade 68.

The plunger is now released, and the spring 70, tending to expand, willshift the plunger to the right in Fig. 11. This will cause the thread tobe engaged by the hook 72 and pulled through the eye of the needle inthe manner shown in Fig. 12.

One now shifts the block 46 and the member 32 upwardly, back to theirFig. 2 position, and this will pull the thread that is engaged by hook72 upwardly, exposing the same-so that it can be cut. The needle willnow be threaded and the sewing operation may continue as before.

It will be seen that the construction is such as to facilitate thethreading of the needle in a minimum amount of time, and it is notnecessary that one make any posi? tive effort to align, the block withthe needle. Nor is it necessary that one make any positive effort tovisually locate the thread relative to the needle threading means. In.other words, the necessity for exact positioning of any part of thethreading means by visual determinationis,

dispensed with, and the threading operation is carried out, as a result,with a minimum of difficulty or loss oftime. In Fig. 17 the spring 70 isshown in the couuterbore 56 about the plunger 62' between the collar 66and the. screw cap 69 so as to force the hook 72 through the eyeof theneedle 40' automatically as the eye of the needle reaches alignment withthe hook 72. The hook 72 is then released by pulling the button 64' ofplunger62 in the direction of the arrow.

While I have illustrated and described the preferred embodiments of myinvention, it is to' be understood that I do not limit myself to theprecise constructions herein" disclosed and that various changes andmodifications may be made within the scope of the invention as definedin the appended claims.

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent is:

1. A needle threading attachment for sewing machines comprising, incombination with a needle post a needle supported by said post, tubularmeans receiving said post, and means carried by the tubular meansadapted to engage a thread and draw the same through the eye of saidneedle, said tubular means being formed as an open-ended tube having adetachable connection to said post, said second means including a blocksupport member slidably mounted in the tube and extending outwardlythereof to shift'longitudinally thereof, a block carried by said blocksupport member, and plunger means slidably mounted inside the block,said member when shifted to one position being adapted to dispose theblock and plunger means in alignment with the eye of the needle, forextension of the plunger means through said eye, said second meansfurther including a guide pin carried by the tube, the block supportmember having a longitudinal closed slot therealong through which theguide pin extends, whereby to limit movement of the member in oppositedirections, the guide pin when engaging against one end of the slotbeing adapted to stop the movement of the block support member wherebysaid member is in a position in which said plunger means is aligned withthe eye of the needle, the block projecting laterally from one end ofthe block support member below the slot and said plunger being shiftablehorizontally within the block, the plunger being spring loaded formovement to one position within the block, the plunger means in said oneposition being disposed clear of the path of the needle.

2. A needle threading attachment for sewing machines comprising, incombination with a needle post a needle supported by said post, tubularmean receiving said post, and means carried by the tubular means adaptedto engage a thread and draw the same through the eye of said needle,said tubular means being formed as an open-ended tube having adetachable connection to said post, said second means including a blocksupport member slidably mounted in the tube and extending outwardlythereof to shift longitudinally thereof, a block carried by said blocksupport member, and plunger means slidably mounted inside the block,said member when shifted to one position being adapted to dispose theblock and plunger means in alignment with the eye of the needle, forextension of the plunger means through said eye, said second meansfurther including a guide pin carried by the tube, the block supportmember having a longitudinal closed slot therealong through which theguide pin extends, whereby to limit movement of the member in oppositedirections, the guide pin when engaging against one end of the slotbeing adapted to stop the movement of the block support member wherebysaid member is in a position in which said plunger means is aligned withthe eye of the needle, the block projecting laterally from one end ofthe block support member below the slot and said plunger being shiftablehorizontally within the block, the plunger being spring loaded formovement to one position within the block, the plunger means in said oneposition being disposed clear of the path of the needle, said plungermeans including a blade-like extension proportioned to extend throughthe eye of the needle when the plunger is shifted against the restraintof its spring to an opposite extreme position.

3. A needle threading attachment for sewing machines comprising, incombination with a needle post a needle supported by said post, tubularmeans receiving said post, and means carried by the tubular meansadapted to engage a thread and draw the same through the eye of saidneedle, said tubular means being formed as an openended tube having adetachable connection to said post,

said second means including a block support member slidably mounted onthe tube and extending outwardly thereof to shift longitudinallythereof, a block carried by said block support member, and plunger meansslidably mounted inside the block, said member when shifted to oneposition being adapted to dispose the block and plunger means inalignment with the eye of the needle, for extension of the plunger meansthrough said eye, said second means further including a guide pincarried by the tube, the block support member having a longitudinalclosed slot therealong through which the guide pin extends, whereby tolimit movement of the member in opposite directions, the guide pin whenengaging against one end of the slot being adapted to stop the movementof the block support member whereby said member is in a position inwhich said plunger means is aligned with the eye of the needle, theblock projecting laterally from one end of the block support memberbelow the slot and said plunger being shiftable horizontally within theblock, the plunger being spring loaded for movement to one positionwithin the block, the plunger means in said one position being disposedclear of the path of the needle, said plunger means including ablade-like extension proportioned to extend through the eye of theneedle when the plunger is shifted against the restraint of its springto an opposite extreme position, said extension being formed with a hookadapted to engage the thread, whereby to draw the thread through the eyeof the needle when the plunger is permitted to return under spring biasto its normal, first-named position.

4. A needle threading attachment for sewing machines comprising, incombination with a needle post, a needle supported by said post, tubularmeans receiving said post, and means carried by the tubular meansadapted to engage a thread and draw the same through the eye of saidneedle, said tubular means being formed as an open-ended tube having adetachable connection to said post, said second means including a blocksupport member slidably mounted in the tube and extending outwardlythereof to shift longitudinally thereof, a block carried by said blocksupport member, and plunger means slidably mounted inside the block,said member when shifted to one position being adapted to dispose theblock and plunger means in alignment with the eye of the needle, forextension of the plunger means through said eye, said second means further including a guide pin carried by the tube, the block support memberhaving a longitudinal closed slot there along through which the guidepin extends, whereby to limit movement of the member in oppositedirections, the guide pin-when engaging against one end of the slotbeing adapted to stop the movement of the block support member wherebysaid member is in a position in which said plunger means is aligned withthe eye of the needle, the block projecting laterally from one end ofthe block support member below the slot and said plunger being shiftablehorizontally within the block, the plunger being spring loaded formovement to one position within the block, the plunger means in said oneposition being disposed clear of the path of the needle, said plungermeans including a blade-like extension proportioned to extend throughthe eye of the needle when the plunger is shifted against the restraintof its spring to an opposite extreme position, said extension beingformed with a hook adapted to engage the thread, whereby to draw thethread through the eye of the needle when the plunger is permitted toreturn under spring bias to its normal, first-named position, theplunger means, at that end thereof remote from said extension,projecting beyond the block and being provided with a button tofacilitate depression of the plunger against the restraint of the springloading thereof.

5. A needle threading attachment for sewing machines comprising, incombination with a needle post, a needle supported by said post, tubularmeans receiving said post, and means carried by the tubular meansadapted to engage a thread and draw the same through the eye of saidneedle, said tubular means being formed as an open-ended tube having adetachable connection to said post, said second means including a blocksupport mem ber slidably mounted in the tube and extending outwardlythereof to shift longitudinally thereof, ,a block carried by said blocksupport member, and plunger means slidably mounted inside the block,said member when shifted to one position being adapted to dispose theblock and plunger means in alignment with the eye of the needle, forextension of the plunger means through said eye, said second meansfurther including a guide pin carried by the tube, the block supportmember having a longitudinal closed slot therealong through which theguide pin extends, whereby to limit movement of the member in oppositedirections, the guide pin when engaging against one end of the slotbeing adapted to stop the movement of the block support member wherebysaid member is in a position in which said plunger means ,is alignedwith the, eye of the needle, the block projecting laterally from one endof the block support member below the slot and said plunger beingshiftable horizontally within the block, the plunger being spring loadedfor movement to one position Within the block, the plunger means, insaid one position being disposed clear of the path of the needle, saidplunger means including a blade-like extension proportioned to extendthrough the eye of the needle when the plunger is shifted against therestraint of its spring to an opposite extreme position, said extensionbeing formed with a hook adapted to engagethe thread, whereby to drawthe thread through the eye of the needle, when the plunger is permittedto return under spring bias to its normal, first-named position, theplunger means, at that end thereof remote from said extension,projecting beyond the block and being provided with a button tofacilitate depression of the plunger, against the restraint ofthe springloading thereof, said block including a pivoted detent, the tube havinga circumferential groove engaging said detent when the block and blocksupport member are shifted longitudinally of the tube out of aneedle-threading position.

6. A needle threading attachment for sewing machines comprising, incombination witha needle post, a needle supported by said post, tubularmeans receiving said post,

and means carried by the tubular means adapted to engage a thread anddraw the same through the eye of said needle, said tubular means beingformed as an openended tube having a detachable connection to said post,said second means including a block support member slidably mounted inthe tube and extending outwardly thereof to shift longitudinallythereof, a block carried by said block support member, and plunger meansslidably mounted inside the block, said member when shifted to oneposition being adapted to dispose the block and plunger means inalignment with the eye of the needle, for extension of the plunger meansthrough said eye, said second means further including a guide pincarried by the tube, the block support member having a longitudinalclosed slot therealong through which the guide pin extends, whereby tolimit movement of the member in opposite directions, the guide pin whenengaging against one end of the slot being adapted to stop the movementof the block support member whereby said member. is in a position inwhich said plunger means is aligned with the eye of the needle, theblock projecting laterally from one end of the block support memberbelow the slot and said plunger being shiftable horizontally within theblock, the plunger being spring loaded for movement to one positionwithin the block, the plunger means in said one position being disposedclear of the path of the needle, said plunger means including ablade-like extension proportioned to extend through the eye of theneedle when the plunger is shifted against the restraint of its springto an opposite extreme position, said extension being formed with a hookadapted to engage the thread, whereby to draw the thread through the eyeof the needle when the plunger is permitted to return. under spring biasto its normal, first-named position, the plunger means, at that endthereof remote from said extension, projecting beyond the block andbeing provided with a button to facilitate depression of the plungeragainst the restraint of the spring loading thereof, said blockincluding a pivoted detent, the tube having a circumferential grooveengaging said detent when the block and block support member are shiftedlongitudinally of the tube out of a needle-threading position, saidthreading attachment including remote control means for releasing thedetent from engagement in the groove.

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